Treatment of Cystine Nephrolithiasis with Alpha-Mercapto-Propionylglycine

The overall frequency of cystine stone formers is 1–6% of stone forming patients1, 2. Cystine stones form by the precipitation of cystine when present in excess in the urine. Cystinuria is an inherited disorder of amino acid transport affecting the epithelial cells of the renal tubules and gastrointestinal tract. The estimated incidence in the general population varies from 1:200 to 1:1370, but patients in whom cystine stones form comprise only 3 to 59 % of all cystinuric patients3-6. Extracorporeal shock wave lithotripsy, electrohydraulic and ultrasonic endoscopic lithotripsy and pulsed dye lasers have limited efficacy in pulverizing cystine calculi owing to its uniform crystal structure. On the contrary, pharmacological treatment of cystine calculi is possible due to new, more effective drugs with fewer side effects. We used α-mercaptopropionylglycine (α-MPG) for cystinuric patients and we have obtained favorable results, as reported in this paper.